Remotely controlled actuators such as, for example, garage door openers are known in the art. These actuators may be activated by one or more transmitters where each transmitter is associated with a unique transmitter code. In order for an actuator to respond to a particular transmitter, a receiver associated with the actuator must generally learn the code of the transmitting transmitter. The learning is generally accomplished by storing the transmitter code in a memory associated with the receiver.
Current technology allows a garage door opener to respond to multiple transmitters with multiple codes by storing the multiple codes in a receiver-memory that has a limited number of memory locations. When a code to be learned is received by the receiver, a memory location is identified via a location pointer. The transmitter code is then stored into the identified memory location and the location pointer is incremented to a next memory location for storing a next code to be learned. If the last memory location has been reached, the location pointer loops back to the beginning of the memory.
One disadvantage of the current technology is that once all the memory locations have been filled with codes, the learning of a new code causes the new code to overwrite a previously stored old code, causing the receiver to no longer respond to a transmitter with the old code.
It is therefore desirable to have an actuator that responds to multiple transmitters with different codes that does not suffer the risk of disabling previously used transmitters upon activation of a new transmitter.